Psoriasis is the most common T helper cell type 1 (Th-1) autoimmune disease, affecting over 2% of the adult population. Similar to other major chronic illnesses, psoriasis is associated with significant decrements in health related quality of life. Psoriasis is characterized by thick, red, scaly skin plaques which can be localized or widespread and an inflammatory arthropathy in some patients. For over 30 years, investigators have suggested that psoriasis may be associated with an increased risk of myocardial infarction, however, there have been no studies evaluating this association using population-based methods and multivariable analysis to control for potential confounding variables. We have developed compelling preliminary data that psoriasis may be an independent risk factor for developing MI. Increasing evidence has linked Th-1 inflammatory pathways to the development of atherosclerosis and ultimately, myocardial infarction, suggesting that the pathophysiology of psoriasis may confer an independent risk for myocardial infarction. In fact, other Th-1 diseases, such as rheumatoid arthritis, have been shown to be independent risk factors for myocardial infarction. We propose to conduct a series of population-based cohort studies to determine if patients with psoriasis have a higher prevalence of cardiovascular risk factors, poorer control of cardiovascular risk factors, and an increased risk of myocardial infarction, stroke, and cardiovascular mortality compared to patients without psoriasis. Studying the relationship between psoriasis, cardiovascular risk factors, and cardiovascular outcomes will have important implications as to our understanding of the relationship between inflammatory diseases and myocardial infarction and will have potentially important public health implications for the care of the over 7 million US patients with psoriasis. PUBLIC HEALTH RELEVANCE: Psoriasis is the most common Th-1 autoimmune disease, affecting over 7 million Americans. The inflammation associated with psoriasis may lead to other conditions in which the immune system plays a role such as atherosclerosis and heart attack. In this application, we aim to perform a large population-based cohort study in patients with varying degrees of psoriasis severity to determine the impact this chronic disease has on the risk of myocardial infarction, stroke, and cardiovascular death. The application is innovative in that we will use a well-validated medical records database system in the United Kingdom to investigate our hypotheses which markedly increases the efficiency of the study and improves the validity of the findings. Furthermore, to our knowledge, this will be the first analytic study of the risk of stroke in patients with psoriasis, and the first study to examine how psoriasis skin severity impacts the risk of MI.